The Neil Gehrels Swift Observatory

Gamma-ray bursts (GRBs) are the most powerful explosions the Universe has seen since the Big Bang. They occur approximately once per day and are brief, but intense, flashes of gamma radiation. They come from all different directions of the sky and last from a few milliseconds to a few hundred seconds. So far scientists do not know what causes them. Do they signal the birth of a black hole in a massive stellar explosion? Are they the product of the collision of two neutron stars? Or is it some other exotic phenomenon that causes these bursts?

With Swift, a NASA mission with international participation, scientists have a tool dedicated to answering these questions and solving the gamma-ray burst mystery. Its three instruments give scientists the ability to scrutinize gamma-ray bursts like never before. Within seconds of detecting a burst, Swift relays its location to ground stations, allowing both ground-based and space-based telescopes around the world the opportunity to observe the burst's afterglow. Swift is part of NASA's medium explorer (MIDEX) program and was launched into a low-Earth orbit on a Delta 7320 rocket on November 20, 2004. The Principal Investigator is Dr. Brad Cenko (NASA-GSFC).

NASA's Swift Catches First Ultraviolet Light from a Gravitational-Wave Event

On 2017 October 16th, the advanced LIGO and Virgo gravitational wave observatories announced the discovery of a new type of gravitational wave signal, likely caused by the collision of two neutron stars. The gravitational wave event occurred on 2017 August 17th, and was accompanied by a gamma-ray burst of short duration. Astronomers across the world began searching for the precise location of this event, quickly tracking it down to the nearby galaxy NGC 4993. Once pin-pointed, the Swift satellite quickly maneuvered to look at the object with its X-ray and UV/optical telescopes. The spacecraft saw no X-rays - a surprise for an event that produced higher-energy gamma rays. Instead, it found a bright and quickly fading flash of ultraviolet (UV) light. This bright UV signal was unexpected and revealed unprecedented details about the aftermath of the collision. The short-lived UV pulse likely came from material blown away by the short-lived disk of debris that powered the gamma-ray burst. The rapid fading of the UV signal suggests that this outflow was expanding with a velocity close to a tenth of the speed of light. The results of the Swift observations were published today on the journal Science. The discovery of this powerful wind was only possible using light, which is why combining gravitational waves and light in what we call 'multi-messenger astronomy' is so important. Credit: NASA/Swift

Latest Swift GRBs

Latest Swift News

Nov 8, 2018

Swift data help to reveal the final stages of colliding black holes

The Burst Alert Telescope aboard the Neil Gehrels Swift Observatory continuously scans the sky producing one of the most sensitive all-sky surveys in the hard X-rays. The survey is especially useful at finding nearby active galaxies, even those obscured at other wavelengths by gas and dust. Using high resolution IR observations of active galaxies detetected with BAT, a team of astronomers found a surprising number of galaxies in the final stages of merging together into single, larger galaxies. Peering through thick walls of gas and dust surrounding the merging galaxies' messy cores, the research team captured pairs of supermassive black holes drawing closer together before they coalescence into one giant black hole. It is not easy to find galactic nuclei so close together. Most prior observations of merging galaxies have caught the coalescing black holes at earlier stages, when they were about 10 times farther away. When the black holes finally do collide, they will unleash enormous energy in the form of gravitational waves.+ Read More

Oct 16, 2018

All in the Family: Kin of Gravitational-Wave Source Discovered by NASA's Satellites

About a year ago, astronomers excitedly reported the first detection of electromagnetic waves, or light, from a gravitational wave source. Now, a year later, researchers are announcing the existence of a cosmic relative to that historic event. GRB150101B was a gamma-ray burst that lasted less than a second, localized by the NASA's Neil Gehrels Swift Observatory in an old elliptical galaxy 1.7 billion years away. The apparent match between GRB 150101B and GW170817 is striking: both produced an unusually faint and short-lived gamma ray burst, and both were a source of bright, blue optical light lasting a few days, and X-ray emission lasted much longer. The host galaxies are also remarkably similar. Both are bright elliptical galaxies with a population of stars a few billion years old and displaying no evidence for new stars forming. A paper reporting the results was published today in Nature Communications.+ Read More

Aug 21, 2018

Swift Millionth Image Mosaic

The Ultraviolet/Optical Telescope (UVOT) aboard the Neil Gehrels Swift Observatory captured its millionth image on May 13, 2018. It took an image of an active galaxy called 2MASX J16110570+0234002, which scientists think exhibited some unusual behavior. A mosaic, created using images UVOT has taken since Swift launched in 2004, celebrates this major milestone for the mission.+Read More